Nanomaterials by severe plastic deformation: review of historical developments and recent advances

International audienceSevere plastic deformation (SPD) is effective in producing bulk ultrafine-grained and nanostructured materials with large densities of lattice defects. This field, also known as NanoSPD, experienced a significant progress within the past two decades. Beside classic SPD methods such as high-pressure torsion, equal-channel angular pressing, accumulative roll-bonding, twist extrusion, and multi-directional forging, various continuous techniques were introduced to produce upscaled samples. Moreover, numerous alloys, glasses, semiconductors, ceramics, polymers, and their composites were processed. The SPD methods were used to synthesize new materials or to stabilize metastable phases with advanced mechanical and functional properties. High strength combined with high ductility, low/room-temperature superplasticity, creep resistance, hydrogen storage, photocatalytic hydrogen production, photocatalytic CO2 conversion, superconductivity, thermoelectric performance, radiation resistance, corrosion resistance, and biocompatibility are some highlighted properties of SPD-processed materials. This article reviews recent advances in the NanoSPD field and provides a brief history regarding its progress from the ancient times to modernity

Determinants of premature mortality in a city population: An eight-year observational study concerning subjects aged 18–64

Background: Premature deaths constitute 31.1% of all deaths in Łódź. Analysis of the causes of premature deaths may be helpful in the evaluation of health risk factors. Moreover, findings of this study may enhance prophylactic measures. Material and Methods: In 2001, 1857 randomly selected citizens, aged 18-64, were included in the Countrywide Integrated Noncommunicable Diseases Intervention (CINDI) Programme. In 2009, a follow-up study was conducted and information on the subjects of the study was collected concerning their health status and if they continued to live in Łódź. The Cox proportional hazards model was used for evaluation of hazard coefficients. We adjusted our calculations for age and sex. The analysis revealed statistically significant associations between the number of premature deaths of the citizens of Łódź and the following variables: a negative self-evaluation of health - HR = 3.096 (95% CI: 1.729-5.543), poor financial situation - HR = 2.811 (95% CI: 1.183‑6.672), occurring in the year preceding the study: coronary pain - HR = 2.754 (95% CI: 1.167-6.494), depression - HR = 2.001 (95% CI: 1.222-3.277) and insomnia - HR = 1.660 (95% CI: 1.029-2.678). Our research study also found a negative influence of smoking on the health status - HR = 2.782 (95% CI: 1.581-4.891). Moreover, we conducted survival analyses according to sex and age with Kaplan-Meier curves. Conclusions: The risk factors leading to premature deaths were found to be highly significant but possible to reduce by modifying lifestyle-related health behaviours. The confirmed determinants of premature mortality indicate a need to spread and intensify prophylactic activities in Poland, which is a post-communist country, in particular, in the field of cardiovascular diseases

Severe plastic deformation for producing superfunctional ultrafine-grained and heterostructured materials: An interdisciplinary review

Ultrafine-grained and heterostructured materials are currently of high interest due to their superior mechanical and functional properties. Severe plastic deformation (SPD) is one of the most effective methods to produce such materials with unique microstructure-property relationships. In this review paper, after summarizing the recent progress in developing various SPD methods for processing bulk, surface and powder of materials, the main structural and microstructural features of SPD-processed materials are explained including lattice defects, grain boundaries and phase transformations. The properties and potential applications of SPD-processed materials are then reviewed in detail including tensile properties, creep, superplasticity, hydrogen embrittlement resistance, electrical conductivity, magnetic properties, optical properties, solar energy harvesting, photocatalysis, electrocatalysis, hydrolysis, hydrogen storage, hydrogen production, CO2 conversion, corrosion resistance and biocompatibility. It is shown that achieving such properties is not limited to pure metals and conventional metallic alloys, and a wide range of materials are currently processed by SPD, including high-entropy alloys, glasses, semiconductors, ceramics and polymers. It is particularly emphasized that SPD has moved from a simple metal processing tool to a powerful means for the discovery and synthesis of new superfunctional metallic and nonmetallic materials. The article ends by declaring that the borders of SPD have been extended from materials science and it has become an interdisciplinary tool to address scientific questions such as the mechanisms of geological and astronomical phenomena and the origin of life

Materiały z pamięcią kształtu jako człony wykonawcze w siłowniku Braillea

The objective of this paper is to show a designing process for actuators that utilizes shape-memory materials. Analytical studies are carried out to design a dot actuator to be used in an electronic Braille display. Shape-memory materials are a relatively new group of smart materials that exhibit the transformation of their internal structures in solid state phases resulting from external mechanical or thermal excitation. This unique property shows up as three phenomena: one- and two-way memory effects as well as superelasticity, which all significantly influence the change of both the mateńal properties and geometry. Hence, shape-memory mateńals are used as actuators effectively controlled by the above-mentioned types of excitation. The work presents the design guidelines for a proposed technical solution as well as the phenomenon utilized in the elaborated model of the actuator. The authors derived the mathematical descriptions for the proposed design configuration and an example of the calculations is shown. Moreover, the characteristics of the elaborated configuration are also discussed, taking into account the range of application areas.W artykule przedstawiono proces projektowania siłowników zbudowanych z materiałów z pamięcią kształtu z zastosowaniem metod analitycznych na przykładzie członu wykonawczego punktu Braille'a stosowanego w elektronicznych wyświetlaczach alfabetu Braille'a. Materiały z pamięcią kształtu są stosunkowo nową grupą materiałów inteligentnych, które charakteryzują się przebudową struktury wewnętrznej w fazach stałych na skutek zewnętrznego wymuszenia mechanicznego lub termicznego. Ta szczególna własność widoczna jest w trzech zjawiskach: jednokierunkowego oraz dwukierunkowego efektu pamięci kształtu oraz supersprężystości, które istotnie wpływają na zmianę wartości parametrów materiałowych oraz geometrię. W efekcie materiały z pamięcią kształtu znajdują zastosowanie jako napędy w członach wykonawczych, w których skok siłownika jest funkcją jednego z wyżej wymienionych wymuszeń. W artykule przedstawiono założenia projektowe zaproponowanego rozwiązania technicznego oraz omówiono zjawisko wykorzystywane w opracowanym modelu. Autorzy wyprowadzili odpowiednie zależności ilościowe dla przyjętej konfiguracji siłownika, których użycie zaprezentowano na przykładzie obliczeniowym. Poddano dyskusji charakterystyki zaproponowanej konfiguracji projektowej, z uwzględnieniem obszaru jej zastosowania

Appliance of volatile analysis technique HS-SPME-GC/MS in the studies of authenticity of chosen food products

Na podstawie badań własnych wykonanych w ostatnich latach dokonano przeglądu możliwości wykorzystania techniki analizy fazy nadpowierzchniowej (head-space) za pomocą mikroekstrakcji do fazy stałej (SPME - solid phase microextraction) i analizy na drodze chromatografii gazowej sprzężonej ze spektrometrią mas. Obiektami badań były kawy Arabica i Robusta, sery pleśniowe, bio-oleje roślinne oraz sery pleśniowe. Celem pracy była ocena przydatności wybranych wyróżników składu chemicznego ziarna kawowego do rozróżniania kaw różnych gatunków i o różnym pochodzeniu geograficznym oraz serów pleśniowych. W zależności od obiektów, badania związków lotnych uzupełniano badaniami innych związków występujących w matrycy żywnościowej m.in.: steroli, składu kwasów tłuszczowych. Uzyskane wyniki poddane zostały statystycznej analizie składowych głównych (PCA). W oparciu o analizę związków lotnych uzyskano dość wyraźne grupowanie pod względem pochodzenia geograficznego. Wskazano również na możliwości wykorzystania techniki HS-SPME-GCMS jako specyficznego i skutecznego e- Nosa dla celów autentyczności i identyfikowalności produktów spożywczych. Dotychczasowe rezultaty badań wskazują na dalsze, różnorodne możliwości zastosowania sprzężonych technik analitycznych w analizie jakości i bezpieczeństwa żywności.Our work carried out in recent years was scoped to investigate the possible use of solid-phase head space micro extraction techniques coupled to gas chromatography - mass spectrometry to the food analysis. The aim of this study was to evaluate the usefulness of the product chemical composition as a factor allowing to distinguish different species of coffee and blue cheeses and differentiate its geographical origin. Arabica and Robusta coffee, blue cheese and various bio-oils samples were taken into investigation. Composition of the volatile headspace fraction was determined. Additional chemical analysis including determination of the fatty acid composition and sterol contents was also performed. Obtained results were statistically analyzed applying principal component analysis (PCA). Results of this study revealed that determination of the volatile fraction composition was sufficient to differentiate the sample geographical origin, and the fairly clear grouping was obtained. The possibility of HS-SPME technique GC-MS as a specific and effective e-nose for authenticity and traceability of food products was also indicated. Results of this and previous research indicate various further possibilities of the combined analytical techniques application in the area of food quality and food safety